Avacon was contracted by Purena GmbH to renew the telecontrol systems for monitoring the water supply at the Rote Bleiche waterworks in Lüneburg. Purena is one of the largest water companies in Lower Saxony and a service provider to local authorities and industrial businesses.
The Rote Bleiche waterworks had the demanding task of securing the water supply from two remote water source areas with 13 sources providing an average of 1,200 m³ per hour. As the water is naturally of a high quality, it only has to have surplus iron, manganese, hydrogen sulphide and natural carbon dioxide removed. After that treatment it is pumped into two purified water holding reservoirs with a capacity of 2,000 m³ each. They balance out the fluctuations in demand and supply the water system for the town of Lüneburg, the Lüneburg South water procurement group and the community of Ostheide plus the Steinhöhe main purified water reservoir, which has a capacity of 12,000 m³.
During replacement of the telecontrol equipment at the water sources, water towers and waterworks, the data transmission requirements in terms of security and redundant back-up increased. In that connection, Matthias Menzel, Alfred Ködderitzsch and Sven Tuband from Avacon achieved a real master-stroke by adapting the systems in telecontrol and control system terms to the stricter requirements using the Soft PLC codeIT application integrated in the setIT confi guration tool entirely on their own.
At the waterworks control centre two FW-50 units were installed as redundant master stations. All water sources are connected in parallel to both master stations via dedicated lines. That means that if a measured data from one of the sources is not received via one channel it is received by the other unit on the other channel. The master stations actively synchronise with each other. The water towers are linked by even more comprehensive security mechanisms. The local telecontrol systems are mirrored for redundant back-up and connected via separate channels to the master stations. The main channel uses WT modems (FSK) and dedicated lines while the secondary channel is a radio link via GPRS.
The redundant back-up confi guration in the central master stations is designed so intelligently that if there is a change-over from standby to active mode, the control function between the water sources and the water towers is also actively taken over immediately by the new leading master. A reliable water supply is guaranteed by an intelligent PLC function in codeIT and the net-line FW-50 stations as redundant telecontrol interfaces.